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View Full Version : Replacement/Retrofitting of Heating and Cooling Systems



Chris_Norway
26-05-2009, 09:03 AM
Hi,

I do not have a technical background in mechanical engeneering, however I'm trying to get an understanding of the technical difficultries/barriers when replacing an existing heating system in an office building 5'000 - 10'000m2.


Let say the building today has a gas burner and a seperate chiller system. Which I found to be the most common in European office building of this size.

In a situation like this, it seem to be two main choices when replaceing/retrofitting the heating/cooling system: (correct me if I am wrong at any point)


1. Replace the burner itself with a better and more efficient burner/boiler. (By far the cheapest option)



2. Retrofit a heat pump system, either a air-to-air, air-to-water, or a geo-thermal heat pumps system.

2a. With an air-to-air heat pump, you would normally need to change the existing ductwork as a heat pump system would need a larger duct size than the existing for both heating and cooling.

2b. With a Air-to-water heat pump, you would either need a new low-temperature radiator system. As the existing radiator system is built for higher temperature gas burn systems. Or you would need a gas burner/ el-coil to heat the water up from 50C to 80C. This would lead to the heat pump to cover only 70% of the heating demand and the rest would be taken by the gas-burner/el-coil.

2c. Retrofitting a geo-thermal heat pump, would be difficult as finding the space to dig wells can be hard after the building is built. It will also have the same issues as 2b, in terms of the new radiator system.


Is it fair to say that after 20 years, you can still use the existing radiator system / ductwork. And therefore a simple replacement of the gas-burner, would be a cheaper option even in the long term. Than to retrofitt a heat pump system into an existing office building of 5'000 - 10'000m2?